How to generate HTTP Signature correctly in CyberSource REST API?

[kelwin54]

To generate an HTTP Signature in CyberSource REST API, developers must create a SHA 256 digest of the request body and include required headers like host, date, digest, and v c merchant id. The signature string is then signed using the merchant’s secret key with HMAC SHA256 encoding. Ensure the header order matches CyberSource documentation exactly, or authentication will fail. Common mistakes include incorrect timestamps, invalid digest values, and missing headers. Always test signatures in the CyberSource sandbox environment before moving to production to verify request authentication and API connectivity properly.

[little]

To generate an HTTP Signature correctly in CyberSource REST API, create a SHA-256 digest of the request body, include the required headers, and sign the signature string using your merchant secret key. This helps ensure secure and authenticated API requests.

[WilliamsWelsh]

A common issue with CyberSource HTTP Signature generation is that even a small mismatch in the canonical string can result in authentication failures. Double-check that the (request-target), host, date, digest (for requests with a body), and header order exactly match the values included in the Signature header. Also ensure the Digest is generated from the raw request body and that the same payload is sent without modification. Logging the complete signature string before signing can make troubleshooting much easier.